#define _CRT_SECURE_NO_WARNINGS 1
//1~100所有带9的数字

#include<stdio.h>

int main()
{
	int a;
	int count = 0;
	for (a = 9; a <= 100; a++)
	{
		if (9 == a % 10||9==a/10)
		{
			count++;
		}
	}
	printf("%d\n", count);
	return 0;
}